Trap-door for cars.



W. H. MUSSEYL TRAP DOOR FOR CARS.

APPLICATION FILED MAR. 11. I915.

Patented M. 24,1916.

.2 SHEETSSHEET I INVENTOR A TTORIVEYS.

mu Mums l-z'rsns ca. Momuma" w4swe mu. 5 c.

W. H. MUSSEY. TRAP DOOR FOR CARS. APPLICATION FILED MAR. 11, I915.

Patented Oct. 24, 1916.

2 SHEETS-SHEET 2.

WITNESSES lA/l/E/VTOI? K Q maxwmmu BY m W. ATTORNEYS.

WILLIAM H. MUSSEY, OF MORRIS PARK, NEW YORK.

TRAP-DOOR FOR CARS.

Specification of Letters Patent.

Patented (lot. 24, 1916.

Application filed March 11, 1915. Serial No. 13,760.

To all whom it may concern:

Be it known that I, VVILLIAM H. MUssEY, a citizen of the United States, residing in Morris Park, county of Queens, Long Island, and State of New York, have invented certain new and useful Improvements in TrapDoors for Cars; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention is directed to the provision of an improved form of spring-actuated hinge adapted to open or close a door automatically when the door is released.

The special object of the invention is to provide an improved form of hinge for use in supporting the trap door of a vestibuled railway passenger car adapted for elevated or grade level platforms. Such a trap door is mounted by means of hinges upon the end wall of the car and is normally disposed horizontally over the steps in continuation of the floor of the car so as to com plete the floor of the vestibule and so that passengers may walk directly from the car to the elevated or grade level platform. When desired, the door may be turned on its hinges to an upright or vertical position close to the end wall of the car to permit unobstructed use of the steps. Such trap doors are usually held in the closed or horizontal position by a latch and are provided with springs to lift them automatically to an open position when the latch is released.

This invention involves the provision of a novel form of hinge for such'trap doors having a spring which is adapted to raise the door to an open position when the door is released. The spring is mounted within a hollow casing, one part of-which is secured to the door and the other part tothe wall The spring table and adapted to ,door and the other or other support for the door. is arranged to effect aXial movement of one of two members which are mounted within the hollow casing and which coact in such a way that axial movement of one effects rotational movement of the other. This co action of the twomembers is preferably at of the members and corresponding helica ribs entering said slots on the other. thermore, one

other is secured to the other part of the cas ing. By this construction,

of the two members is splined l to one part of the hollow casing, whereas theta when the door the junction of the two parts is closed, the spring is under compression tending to move the splined member axially and such movement occurs when the latch of the door is released; such axial movement operates through the helical ribs and grooves to cause rotational movement of the other member and the part of the casing to which it is secured, thus turning the door to the open position.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which- Figure 1 is a diagrammatic view in elevation of a portion of the end of a railway passenger car; Fig. 2 is a view in end elevation of the hinge for supporting the trap door; Fig. 3 is a sectional view on line 33 of Fig. 2 showing the construction of the hinge and the manner in which the door is supported; Fig. -i is a sectional view of the hinge showing the parts thereof in the positions they occupy when the door is open; Figs. 5 and 6 are transverse sectional views on lines 5-5 and 66 of Fig. 3; and Fig. 7 is a perspective view of the two coacting members mounted within the casing of the hinge.

Referring to these a portion of the end platform of the car, the steps 9, and the trap door 10 the latter being shown in its closed position in which it forms a part of the fioor of the vestibule so that passengers may conveniently walk from the vestibule of the car to an'elevated or grade level platform. The trap door 10 is pivotally mounted so that it may be moved to the position indicated by the dotted lines in Fig. 1, in which position it is disposed vertically close to the end wall of the car body.

The hinge for supporting the door 10 comprises a hollow, two-part casing, the two parts 11 and 12 of which are relatively rotabe secured one to the to the supporting wall The part drawings, Fig. 1 shows ecured by bolts 14 to the wall; the part 11 as integral extensions or flanges 15 which may be riveted to the door. The abutting nds of the two parts of the casing are aranged to fit one within the other as shown t 16. The opening in the part 12 is of lightly larger diameter than that in the part 11 so that a shoulder is provided at of the casing.

of the car body 8, the

sists of a cylindrical body having helically casing but is arranged ribs 21 extending therefrom and fitting snugly within the slots or grooves in the coacting member 17. This member 20 may move axially within the part 12 of the prevented from turning relatively thereto by means of a spline connection to the part 12. i v

' As shown in Figs. 5 and 7, the cylindrical portion of the member 20 has axial grooves formed in its surface which grooves receive a suitable latch.

splines 22 secured to the part 12 by screws 28. The member 20 is moved axially within the hollow casing by means of a coiled spring 2-1, one end of which fits within an opening in the cylindrical portion of the member 20 and the other end of which bears against a plug 25, which is threaded in an opening in the end of the casing.

As shown in the drawings, the cylindrical portion of the member 20 is of larger diameter than the ribs projecting therefrom so that a shoulder is formed at the end of the cylindrical portion adapted to abut against the end of the part 11 of the easing to limit the movement of member 20 in that direction. In the present instance, two ribs 21 and coacting slots are shown though one or any other number may be employed if desired; however, I have found it preferable to employ two ribs and grooves and to shape them as is indicated in Fig. 6.

The hinge thus constructed is secured to the door near the outer edge of the latter. Near its inner edge, the door has a pivot 26 secured to the under side thereof, the end of which is received in a journal 27 mounted in the riser of the upper step.

Figs. 1, 2 and 3, show the door in its horizontal or closed position where it is held by In moving the door to this closed position, the turning movement of the part 11 of the casing relatively to the part 12 causes the member 17 in the part 11 to act upon the ribs 21 of the member 20 so as to cause axial movement of the member 20 within the part 12 of the casing, the member 20 being prevented from rotating by its spline connection to the part 12. This axial movement of themember 20 results in compressing the spring124. When it is desired to open the door, the latch is released and the spring 24 moves the member 20 axially to the left in Fig; 3 and the helical ribs 21 act upon the member 17 to rotate the latter and the part 11 of the easing to which it is secured so as to turn the door to an open position. The spring 21 may be arranged to operate in this manner to move the door from the closed position to the upright or vertical position or if desired the proportioning of the parts may be such that the spring will only move the door partially to the upright position; in the latter case, when the door has been partially opened by the spring, its edge may be grasped and the door moved manually to the vertical position. In either case the abutting of the end of member 20 against the shoulder on the part 11 of the casing will limit the swinging movement of the door and prevent slamming of its upper edge against the end wall of the car or the like.

WVhat I claim is:

1. A counterbalanced trap door consisting of a door mounted on a suitable support to swing on a horizontal axis, said axis being eccentrically disposed relatively to the center of gravity of said door, and means for counterbalancing said door comprising relatively rotatable interengaging parts carried by said door and said support respectively with their axis of rotation coincident with the axis of said door, one of saidparts having a spiral cam surface of quick pitch having operative engagement with the other of said parts, one of said parts being mounted for axial movement as effected by the relative rotation of said parts and a spring engaging said movable part and adapted to be compressed by downward movement of said door from vertical to horizontal position to counterbalance the weight of said door in its horizontal position.

2. A counterbalanced trap door consisting of a door mounted on a suitable support to swing on a horizontal axis, said axis being eccentrically disposed relatively to the center of gravity of said door and means for counterbalancing said door, comprising relatively rotatable parts carried by said door and said support respectively with their axis of rotation coincident with the axis of said door, said parts having interengaging spiral tongues and grooves of quick pitch, one of said parts being mounted for axial movement and a spring engaging said movable part and adapted to be compressed by downward movement of said door from vertical to horizontal position, the strength of said spring being suflicient when fully compressed to more than counterbalance the weight of said door in horizontal position.

3. A counterbalanced trap door consisting of a door mounted on a suitable support to swing on a horizontal axis, said axis being eccentrically disposed relatively to the center of gravity of said door, a hinge for said door comprising tubular parts attached to said door and said supportrespectively and mounted one on the other for relative rotation, a core detachably secured against rotation in the bore of one of said parts and provided with spiral cam grooves of quick pitch, a core detachably secured against rotation in the other of said tubular parts and provided with spiral tongues projecting into the grooves of the other core, one of sald cores being mounted for longitudinal movement, and a stiff compression spring inolosed in the bore of the tubular part behind said movable core, and arranged to be compressed by the downward movement of said door to horizontal position.

4. A counterbalance hinge for trap doors comprising tubular parts mounted one on the other for relative rotation, a core detachably secured against rotation in the bore of one of said parts and provided With spiral cam grooves of quick pitch, a core detachably secured against rotation in the other of said tubular parts and provided With spiral tongues projecting into the grooves of the other core, one of said cores being mounted for longitudinal movement, a stiff compression spring inolosed in the bore of the tubular part behind said movable core, and a threaded plug closing the end of said tubular part and engaging the end of said spring for adjusting its tension.

In testimony whereof I aiiix my signature, in presence of tWo Witnesses.

WILLIAM H. MUSSEY. Witnesses R. H. WARD, N. J. CAMPBELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

